Various memory cards loaded with flash memories have been put into practical use, and used for a variety of purposes. As one type of such memory cards, SD (Secure Digital) memory cards have been widely known. The SD memory cards are smaller in size than other memory cards such as PC cards, and have therefore spread as recording media to be used for portable terminal devices such as mobile phones and PDAs.
FIG. 9 is an external perspective view showing a mobile phone as an example of a conventional portable wireless device including a slot for inserting therein an SD memory card. For the mobile phone 5, an upper housing 90 including a liquid crystal display section 91 and a lower housing 80 having a radio circuit are configured so as to be foldable by a hinge portion 92. The mobile phone 5 has, at a side portion of the lower housing 80, a card slot 82 that can be blocked with a slot cover 83, and an SD memory card 500 can be inserted in and removably attached to the card slot 82.
In recent years, SD memory cards have also been diversified, and an SDIO (Secure Digital Input/Output) card with an I/O function has been the focus of attention. The SDIO card is a card type functional medium for which a wireless communication function such as Bluetooth (registered trademark), wireless LAN, or GPS is loaded on an SD memory card, and which is capable of transmitting and receiving data with a plurality of information processing devices. The SDIO card is configured inside with an RF circuit and an antenna element stored to perform wireless communications, and like the SD memory card, is fitted to a card slot of a portable wireless device.
An SDIO card is usually arranged so that its antenna element is located at an entrance side of the card slot 82 so that radio waves can be easily transmitted and received, and when the SDIO card is fitted to the card slot 82, the part of the antenna element is held in a state projecting from the lower housing 80 of the mobile phone 5 (see Patent Document 1, for example).
Moreover, there has been proposed an example where, in order to prevent a part of an SDIO card where an antenna element is located from projecting from the lower housing 80, an antenna is built in an eject lever that is operated to eject the SDIO card (see Patent Document 2, for example).    Patent Document 1: JP-A-2003-6603    Patent Document 2: JP-A-2001-195553